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Motion artifacts are more common during high-speed sequences on programming. This is usually the result of a level of compression that doesn't allow enough data to stream through to update the picture rapidly enough. On a slow sequence such as a news announcement, much of the picture is actually repeated over several frames. In that case, new information for each screen might not be sent and large portions of the picture which remains unchanged between frames will be sent a simple "ditto" command. So, instead of having to re-send every pixel for every frame, they send much less data.

In the case of fast action, a lot of the screen is changed every frame, especially in games like NASCAR and hockey where cameras follow cars or pucks or other high speed objects where the camera pans across an entire field rapidly. This results in data for the entire screen needing to be refreshed for every frame. From a digital perspective, this is very data intense. Programmers often have to balance channels that have lots of high-action (SPEED, NHL) with channels that have low action (TVGUIDE, Weather Channel) and send them down the same transponders to maximize the available space on each transponder. Unfortunately, some programmers will squeeze too much content onto one transponder and when a channel goes unusually high action it strains the pipe. This can happen with providers who are really pressed for bandwidth (cable) and they over compress the signals or if a channel that is normally low action suddenly goes high action and the program provider didn't account for it.

Motion artifacting is completely different from signal issues in general since motion artifacting is an issue that usually originates at the headend whereas as tiling is usually an onsite issue from site-specific trouble issues.

vegassatellite said:

Motion artifacts are more common during high-speed sequences on programming. This is usually the result of a level of compression that doesn't allow enough data to stream through to update the picture rapidly enough. On a slow sequence such as a news announcement, much of the picture is actually repeated over several frames. In that case, new information for each screen might not be sent and large portions of the picture which remains unchanged between frames will be sent a simple "ditto" command. So, instead of having to re-send every pixel for every frame, they send much less data.

In the case of fast action, a lot of the screen is changed every frame, especially in games like NASCAR and hockey where cameras follow cars or pucks or other high speed objects where the camera pans across an entire field rapidly. This results in data for the entire screen needing to be refreshed for every frame. From a digital perspective, this is very data intense. Programmers often have to balance channels that have lots of high-action (SPEED, NHL) with channels that have low action (TVGUIDE, Weather Channel) and send them down the same transponders to maximize the available space on each transponder. Unfortunately, some programmers will squeeze too much content onto one transponder and when a channel goes unusually high action it strains the pipe. This can happen with providers who are really pressed for bandwidth (cable) and they over compress the signals or if a channel that is normally low action suddenly goes high action and the program provider didn't account for it.

Motion artifacting is completely different from signal issues in general since motion artifacting is an issue that usually originates at the headend whereas as tiling is usually an onsite issue from site-specific trouble issues.

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hi there...well what you are saying here totally makes sense to me. But I have a question to somebody then. If satellite companies know that sports channels are very data intensive, why would not they bump up the bandwidth or reduce compressions on those specific channels? Don;t they know that it is almost impossible to watch hi action sports channels they way they set them up? I am sorry but I could care less if the weather channel has a perfect picture, but when I watch sports I want to be able to actualy see what is going on..not trying to find the ball on the screen that disappears because the the data is too much.
how can somebody instill this into the minds of programmers at Dish network??
BTW, I have never seen such problem with cable TV. I guess they understand how bandwidth and compression are so much m,ore important for sports channels than satellite tv who do not understand that.
I wish I could get one of those dish network programmers in the room with me and make him watch tennis channel and then tell me if he enjoyed it or not..or if he could understand what was going on on the court.

so what is the solution..can somebody press dish network to increase bandwidth on certain channels?

andyg said:

hi there...well what you are saying here totally makes sense to me. But I have a question to somebody then. If satellite companies know that sports channels are very data intensive, why would not they bump up the bandwidth or reduce compressions on those specific channels? Don;t they know that it is almost impossible to watch hi action sports channels they way they set them up? I am sorry but I could care less if the weather channel has a perfect picture, but when I watch sports I want to be able to actualy see what is going on..not trying to find the ball on the screen that disappears because the the data is too much.
how can somebody instill this into the minds of programmers at Dish network??
BTW, I have never seen such problem with cable TV. I guess they understand how bandwidth and compression are so much m,ore important for sports channels than satellite tv who do not understand that.
I wish I could get one of those dish network programmers in the room with me and make him watch tennis channel and then tell me if he enjoyed it or not..or if he could understand what was going on on the court.

so what is the solution..can somebody press dish network to increase bandwidth on certain channels?

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Unfortunately, to this observer, Dish seems to have policy regarding compression relative to how large a metro area is. For example, there are countless complaints form many a good folk in lower population areas who complain of VERY bad LIL PQ with lots of Macro pixels.

On the other hand, while there is room for imporvement, the Los Angeles locals range form fair to good, depending upon what kind of display technology being used. Channles 4 and 7 (KNBC and KABC, respectivly) are especially good looking, for LIL's. Channels 9 and 2 (KCAL and KCBS) are somewhat sorry pictures. Satellite has penetrated very highly here in the L.A. metro area.

Can you imagine the phone lines being jammed and everything going down because an L.A. LIL looked as bad as many of our poor friends' LIL's who live in rural areas or small cities? In fact, on the rare occasions that there is a temporary issue on an L.A. LIL local (once audio was out for KNBC for about 5 minutes, just as one example), I've tried to call in and get a busy signal on all occasions. Now, I just don't do a thing because I know at least 10,000 other people are calling in for me.

It's all about the numbers. Fewer people to complain about LIL PQ where the cows come home than in krazy Los Angeles, California. It is not right. You folk in the boonies deserve at least as good LIL PQ as we get here in L.A. And even then, it aint so great lookin'. I forget how many spotbeams are used for LA LIL's (at least 3, maybe 4), but that is only because we have a ton of locals, anyway. Not all in English.

DishSubLA said:

Unfortunately, to this observer, Dish seems to have policy regarding compression relative to how large a metro area is. For example, there are countless complaints form many a good folk in lower population areas who complain of VERY bad LIL PQ with lots of Macro pixels.

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I think this might be because by the time technology came around for spot beams, Dish was pretty much done with "major" markets and moving on to minor and semi-major markets. I think the utilization of spot beams is where they started going for higher compression because of the varying number of locals in different cities. If a particular beam serves two cities but together they have one more than ideal number of channels for that transponder, they may well push the extra compression so they don't have to stuff a LiL channel somewhere else like a ConUS transponder. Market size might have something to do with it, but it is probably just less than ideal conditions such as where the spots are and LiL channel counts in each beam.

Motion artifacts are the plague of digital TV, especially over compressed digital TV.

The limited bandwidth available on OTA channels (6MHz) causes problems for high motion scenes on 1080i transmissions because there is too much going on on the screen for the data rate to keep up with, so the forward error correction fails to keep the picture at a high quality resolution and blocking occurs. The same is true for over compressed satellite signals.

I see it also on PBS (1080i) when they show close-ups of waterfalls or snow scenes. Areas of the picture begin to show squares of various shades instead of random motion.

The compression algorythm fails to correctly interpret areas of the screen where too much motion occurs.

The only way to fix it is more bandwidth or better compression algorythms (MPEG4 is an improvement if done right).

vegassatellite said:

I think this might be because by the time technology came around for spot beams, Dish was pretty much done with "major" markets and moving on to minor and semi-major markets. I think the utilization of spot beams is where they started going for higher compression because of the varying number of locals in different cities. If a particular beam serves two cities but together they have one more than ideal number of channels for that transponder, they may well push the extra compression so they don't have to stuff a LiL channel somewhere else like a ConUS transponder. Market size might have something to do with it, but it is probably just less than ideal conditions such as where the spots are and LiL channel counts in each beam.

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But the new spot beams were designed after that point. furthermore, high population and the economies are related. Perhaps a good example was his renewal of LA local Fox 11 a few years ago. It was a pretty public dispute because Fox wanted lots of money, and I remember that it was related to Fox demanding that Dish take another one of those Fox owned channels (possibly Fox Reality, I'm not sure). KTTV LA Fox 11 crawled the expected nasty rant against Dish.

Now, in smaller markets, Charlie has universally balked at such demands and let a LIL, even a big affiliate, be dropped. But I knew Charlie was gonna have to pay because he would have been flooded with calls and a mass exodus to Direct or even back to cable. I just knew he wouldn't dare allow a major LA LIL to be dropped (excluding the CBS/Viacom stations drop because Congress was in session reviewing LIL legislation and Ergan wanted to make a point with Congress, and it worked). In the past he had given discounts for LIL because a major affiliate was missing, and even installed OTA antennas in some markets so his subs could still view that local that was dropped form the satellite. Could you imagine the red ink if he applied that to Los Angeles?

Sure enough, on the subsequent Charlie Chat, Jim announces a new channel in the AT tier, (the FOX owned channel), and Charlie says, "Yeah, that was a lot of money. I know it cost us a lot of money, anyway" he said much to his chagrin. He continued with a somewhat glum tone looking at his peanut gallery, "Well, it was part of renewing our agreement with the local Fox station in Los Angeles, and that was a lot money, too.!"

While the LIL's PQ in big cities surely leave something to be desired, we just don't get the kinds of complaints on this board form big city dwellers that we do from our good citizens in the less populated parts of the country, and again, the Los Angeles/southern California area has the highest penetration of satellite in the country. And there are dishes (either Direct or Dish) EVERYWHERE around here!.

I may be wrong, but I still believe it is all about the high population and penetration and the economies that affect LIL PQ.

Yeah, but if a LiL is served on a spot beam and they have no other useful programming to put there (can't put national channels on a spotbeam) and the space allows it, why over compress the channels on that spotbeam?